Silencer for outside installation



Oct. 13, 1953 s w z 2,655,220

SILENCER FOR OUTSIDE INSTALLATION Filed April 18 1951 John P. Tyskewicz /n venfor A) orney Patented Oct. 13, 1953 UNITED STATES PATENT OFFICE SILENCER FOR OUTSIDE INSTALLATION John P. Tyskewicz, Hartford, Conn., assignor to The Maxim Silenc Cnn., a corporation 2 Claims. 1

The present invention relates to silencers for diesel or gas engine exhausts where it is desirable to have the silencer mounted outside a building. In such cases the exhaust pipe of the engine usually comes through the wall horizontally at a distance from the ground, and the tail pipe from the silencer usually extends vertically to the top of the building to carry on" the gases. For economical reasons it is desirable to have the silencer supported as close to the ground as possible. The combination of these requirements means that the inlet to the silencer should be horizontal and near the top of the silencer shell, while the outlet from the silencer should leave the shell in a verticaldirection. It is the object of the invention to provide a silencer subject to the conditions above which will have good silencing properties and which will produce only slight back pressure.

The invention will now be described with reference to the accompanying drawings. in which:

Fig. 1 is a side elevation of a silencer with the cylindrical shell and certain other parts broken away on the median plane;

Fig. 2 is a section on line 2-2 of Fig. 1; and

Figs. 3, 4 and 5 are details showing different possible ways of mounting the inlet conduit.

The silencer comprises a cylindrical shell or casing It, preferably of circular cross section, having a top header II and a bottom header l2 which may rest on any suitable foundation. Within the casing is a transverse partition I3 which divides the interior of the shell into a top or inlet chamber I 4 and a bottom 0]: outlet chamber 15, A conduit [6, open at both ends, passes through an aperture in the partition l3 and is supported from the latter as by welding. An outlet conduit ll extends through the header H and i supported by it, and then passes coaxially through the conduit I6 and beyond it to a point near the bottom header H, where it terminates with an open end. The conduit I6 is preferably coaxial with the shell [0, but may if desired be displaced sideways in a direction away from the inlet conduit to be described later. The space between the conduits l6 and I1 forms an annular passage l8 through which the exhaust gas may pass from the inlet chamber 14 to the outlet chamber [5, the conduits being held in the desired relation as by lugs 19.

The side inlet conduit is in the preferred form located well up toward the top of the silencer casing, as shown in Fig. 1, although the silencer functions practically as well with the side inlet near the lower end of the inlet chamber [4 as shown at 202 in Fig. 4. When the inlet con- Company, Hartford,

of Connecticut Application April 18, 1951, Serial N 0. 221,634

nection is near the top, a curved baflle plate 2| is secured adjacent the upper side of the inlet opening and curves downwardly over it. The entering gas is thus directed downwardly away from the open end of the annular passage l8 and has a chance to expand and to even out pressure pulses before passing down through the annular passage 18 into chamber I5. The plate 2| changes the direction of the gas very smoothly until it is nearly parallel to the axis of the silencer, resulting in a better silencing action and a lower back pressure than if the gas were directed circumferentially to produce whirling as is shown for contrast at Eiil in Fig. 3. The downwardly directed inlet conduit of Fig. 5 is substantially the same in its action as the plate 2|. In chamber l5 further evening out of the pulses occurs, and the gas finally passes up the central conduit l1 and out through the outlet connection 22.

Conduit [6 has a row of anti-resonance holes 23 located on the side away from the inlet connection 20, and conduit I! has a row of similar holes 24 located on the side opposite holes 23. This arrangement results in a particularly excellent anti-resonating system, which is assisted by the provision of a slot 25 at the lower end of conduit H. No great amount of gas passes through holes 23 and 24, although they may aid in the smoothing out of high pressure peaks, their main purpose being to suppress the tendency of the gas columns within the annular passage I8 and the conduit I l to resonate at frequencies dependent upon the lengths of these passages. The size and location of the holes should be determined as described in Bourne Patent 2,297,046, September 29, 1942. The conduit ll has a length within the silencer great enough to act as a selfcontained tail pipe, although generally an additional tail pipe is used for the purpose of carrying the gases upwardly the necessary distance. In figuring the length of the conduit I! so that the holes 24 may be located at the half and quarter points as described in the Bourne patent referred to, two thirds of the portion of the conduit containing the slot 25 is omitted since one effect of the slot is to shorten the acoustic length of the conduit IT by approximately the amount indicated above. In the case of the open-ended cylinder is the location of the holes at the half and quarter points is uncomplicated.

What I claim is:

1. A silencer comprising a substantially cylindrical shell having end headers and being divided into an inlet and an outlet chamber by a transverse partition; said silencer having an open- 3 ended cylinder passing through the partition and terminating at each end at a point between the partition and the respective end header, an inlet conduit opening into the inlet chamber adjacent that end of the open-ended cylinder in the inlet chamber, a curved plate secured to the shell adjacent the upper portion of the inlet conduit and curved downwardly'over the opening of said conduit, and an outlet conduit passing through an end header, through a portion of the inlet chamber, through the interior of the open-ended cylinder, through a portion of the outlet chamber, and terminating within the latter at-a'p'oi'nt between the end of the open-ended cylinder and the adjacent end header, said open-ended cylinder being imperforate on the side adjacent the in let conduit and having on the opposite side asingle row of, perforations located at half and quarter points along its length, and the outlet conduit being imperfora'te on said opposite side where it passes through the open-ended cylinder and having on the side adjacent the inlet conduit 21. single row of holes located at half and quarter points along its effective acoustic length.

2. A silencer comprising a substantially cylindrical shell having end headers and being divided into an inlet chamber and an outlet chamber by a transverse partition, said silencer having an open-ended cylinder passing through the partition and terminating at each end at a point between the partitionand the respective end header, an inlet conduit opening into the inlet chamber adjacent that end of the open-ended cylinder in the inlet chamber, a curved plate secured to the shell adjacent the upper portion of the inlet conduit and curved downwardly over the opening of said conduit, and an outlet conduit passing through an end header, through a portion of the inlet chamber, through the interior of the open-ended cylinder, through a portion of the outlet chamber, and terminating within the latter at a, point between the end of the openended cylinder and the adjacent end header, said outlet conduit having a longitudinally extending slot in the portion thereof extending into the outlet chamber beyond the open-ended cylinder and being imperforate on the side opposite the inlet conduit and having a single row of perforations located at half and quarter points along its effective acoustic length within the open-ended cylinder on the side adjacent the inlet conduit, and the said open-ended cylinder being imperforate on the side adjacent the inlet conduit and having a single row of perforations located at half and quarter points along its length on the side opposite the inlet conduit.

JOHN P. TYSKEWICZ.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,580,671 Eschholz Aug. 14, 1928 2,138,510 Rauen Nov. 29, 1938 2,297,046 Bourne A- Sept. 29, 1942 2,323,955 Wilson he July 13, 1943 2,455,965 Wohlberg Dec. 14, 1948 2,511,713 Hoyle et al. "a"--- June 13, 1950 FOREIGN PATENTS Number Country Date 276,074 Great Britain i. Aug. 18,1927 

